1. Field of the Invention
The present invention relates to a rear projection type display apparatus, and more particularly to technology that measures color reproduction characteristics to control image display characteristics.
2. Description of the Related Art
A rear projection type display apparatus is already known in which light receiving sensors for photometric adjustment are provided between a screen member and a projection apparatus (Japanese Patent Laid-Open No. 2005-173424). An outline of this arrangement will be described with reference to FIG. 24A, FIG. 24B, FIG. 25A and FIG. 25B.
FIG. 24A and FIG. 24B are views that show an outline of the arrangement of this kind of rear projection type display apparatus. FIG. 24A is a plan view of an upper notch of a rear projection type display apparatus 1, and FIG. 24B is a view for describing disposition positions of light receiving sensors at a time of photometric adjustment.
In this arrangement, as shown in FIG. 24A, mobile light receiving sensors 81 are disposed between a screen member 7 and a projection apparatus 9 inside an apparatus main unit 8. As shown in FIG. 24A and FIG. 24B, at the time of photometric adjustment the light receiving sensors 81 are moved to positions that are struck by projected light from the projection apparatus 9 to receive the light from the projection apparatus 9. Light that is subjected to photometry at the light receiving sensors 81 is input to a control unit (not shown) and data processing with respect to the level of symmetry of luminance and hue is performed. The luminance and hue are then adjusted based on the data processing results of the control unit. In this connection, movement of the light receiving sensors 81 can be performed manually or electrically.
FIG. 25A and FIG. 25B are state views that show disposition positions of the light receiving sensors 81 at a time of normal use. FIG. 25A is a plan view of an upper notch of the projector apparatus 1 at a time of normal use, and FIG. 25B is a view for describing disposition positions of the light receiving sensors 81 at the time of normal use. As shown in FIG. 25A and FIG. 25B, at a time of normal use of the rear projection type display apparatus 8, the light receiving sensors 81 are moved to positions which are not struck by projection light from the projection apparatus 9 to prevent the light receiving sensors 81 obstructing the light from the projection apparatus 9. As described above, movement of the light receiving sensors 81 can be performed manually or electrically.
However, in the above described arrangement, measurement can only be carried out at the periphery of the screen, and in that condition it is difficult to perform measurement for the entire screen or for an arbitrary position on the screen. In particular, in a thin rear projection apparatus with a large screen or the like, if sensor positions are designed to be movable there is a possibility that the sensors will collide due to dimensional and structural constraints, and realization thereof is difficult.
Therefore, according to the conventional arrangement, due to factors such as the light source and display device of the rear projection apparatus, it is difficult to measure color reproduction characteristics including the luminance, tone and color temperature of a display image across the whole of the display area. Accordingly, a user or a service person cannot appropriately correct inconsistencies in the display without using an external measurement apparatus.